Details

Autor(en) / Beteiligte

• Yu, Areum
• Lee, Chongmok
• Kim, Myung Hwa
• Lee, Youngmi

Titel

Nanotubular Iridium–Cobalt Mixed Oxide Crystalline Architectures Inherited from Cobalt Oxide for Highly Efficient Oxygen Evolution Reaction Catalysis

Ist Teil von

• ACS applied materials & interfaces, 2017-10, Vol.9 (40), p.35057-35066

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Here, we report the unique transformation of one-dimensional tubular mixed oxide nanocomposites of iridium (Ir) and cobalt (Co) denoted as Ir x Co1–x O y , where x is the relative Ir atomic content to the overall metal content. The formation of a variety of Ir x Co1–x O y (0 ≤ x ≤ 1) crystalline tubular nanocomposites was readily achieved by electrospinning and subsequent calcination process. Structural characterization clearly confirmed that Ir x Co1–x O y polycrystalline nanocomposites had a tubular morphology consisting of Ir/IrO2 and Co3O4, where Ir, Co, and O were homogeneously distributed throughout the entire nanostructures. The facile formation of Ir x Co1–x O y nanotubes was mainly ascribed to the inclination of Co3O4 to form the nanotubes during the calcination process, which could play a critical role in providing a template of tubular structure and facilitating the formation of IrO2 by being incorporated with Ir precursors. Furthermore, the electroactivity of obtained Ir x Co1–x O y nanotubes was characterized for oxygen evolution reaction (OER) with rotating disk electrode voltammetry in 1 M NaOH aqueous solution. Among diverse Ir x Co1–x O y , Ir0.46Co0.54O y nanotubes showed the best OER activity (the least-positive onset potential, greatest current density, and low Tafel slope), which was even better than that of commercial Ir/C. The Ir0.46Co0.54O y nanotubes also exhibited a high stability in alkaline electrolyte. Expensive Ir mixed with cheap Co at an optimum ratio showed a greater OER catalytic activity than pure Ir oxide, one of the most efficient OER catalysts.